1. Field of the Invention:
The present invention relates to a reservoir for reserving oil and having a filter for filtering the oil which flows from its inlet to its outlet.
2. Description of the Prior Art:
In general, a reservoir used in an automotive power steering system is provided with an inlet connected to a servovalve of the power steering system and an outlet connected to a pump of the power steering system. In such reservoir, a filter is attached within the reservoir at a location between the inlet and the outlet so as to filter the oil flowing from the inlet to the outlet.
There is a problem in such reservoir that the oil does not flow through the filter smoothly under low temperature environments, because the viscosity of the oil becomes higher in such environments. Under such environments, the flow resistance within a hose connecting the reservoir and the pump also becomes higher than that under normal operation temperatures. As a result, the oil cannot be sufficiently supplied to the pump under such low temperature environments, so that a cavitation tends to be generated in the pump due to the insufficiency of the oil supply. The cavitation causes the pump to produce odd sounds. Although many methods have been tried to reduce the odd sounds, sufficient results have not been obtained.